Keyword: linac
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MOPC06 Beam Diagnostics System for a Photo-Neutron Source Driven by 15MeV Electron Linac electron, beam-position, diagnostics, BPM 57
 
  • Y.B. Yan, J. Chen, Z.C. Chen, Y.B. Leng, L.Y. Yu, R.X. Yuan, W.M. Zhou
    SINAP, Shanghai, People's Republic of China
  
  A photo-neutron source driven by 15MeV electron LINAC is under construction at Shanghai Institute of Applied Physics (SINAP). Several kinds of beam monitors (BPM, Profile and ICT) have been installed. The stripline beam position monitor with eight electrodes was designed, also for energy spread measurement. Due to the multi-bunch operation mode, a custom RF front end was adopted, which down-converts the signal from 2856MHz to 500MHz and then brings it to Libera Single Pass E. The beam position monitor was based on the integrated step-servo motor and GigE Vision camera. For the beam charge measurement we used the ICT from Bergoz and scope from Agilent. The detail of the whole beam diagnostics system development will be reported in this paper.  
 
MOPC13 Design of Cold Beam Position Monitor for CADS Injector II Proton LINAC BPM, cryogenics, proton, alignment 75
 
  • Y. Zhang, X.C. Kang, M. Li, J.X. Wu, G. Zhu
    IMP, Lanzhou, People's Republic of China
  
  Cold beam position monitor based on capacitive buttons are designed for Chinese Accelerator Driven System (CADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Cold button BPM will be installed in the Cryomodule, which will be in the middle of the superconductor cavity and the superconductor magnet. Some special issues must be considered when designing a cold BPM: low-beta beam in the cryogenic environment, strong rf-field from the superconductor cavity and high magnetic field from the superconductor magnet. In this contribution, the status of cold BPM will be presented, focusing on the electromagnetic response for low-beta beams and mechanical design in the cryogenic environment.  
 
MOPC19 Status of the Beam Position Monitors for LIPAc pick-up, BPM, simulation, beam-position 93
 
  • I. Podadera, F.M. De Aragon, A. Guirao, D. Jimenez, A. Lara, L.M. Martinez, J. Molla
    CIEMAT, Madrid, Spain
  
  Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654.
The LIPAc accelerator will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. Several types of Beam Position Monitors –BPM’s- are placed in each section of the accelerator to ensure a good beam transport and minimize beam losses. Prototypes of almost all the BPM’s have been already fabricated. Acceptance tests have been carried out on each device. The output of the vacuum leak tests and electrical tests will be analyzed in this contribution. In addition, the test bench to characterize the BPM’s has been upgraded and validated using some prototypes in order to obtain a better global measurement accuracy of the electrical center offset. The test bench can be used to crosscheck the simulations with the real response of each BPM. The result of the comparison will be discussed in detail. 		 
 
MOPC21 Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring BPM, beam-position, proton, single-bunch 101
 
  • M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh
    GSI, Darmstadt, Germany
  • W. Ackermann
    TEMF, TU Darmstadt, Darmstadt, Germany
  • M.H. Almalki
    IAP, Frankfurt am Main, Germany
  • M.H. Almalki
    KACST, Riyadh, Kingdom of Saudi Arabia
  • B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic
    I-Tech, Solkan, Slovenia
  • C.S. Simon
    CEA/DSM/IRFU, France
  
  The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne4+ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.  
poster icon Poster MOPC21 [1.622 MB]  
 
MOPC36 Test of a Non-Invasive Bunch Shape Monitor at GSI High Current LINAC electron, longitudinal, GSI, MCP 151
 
  • P. Forck, C. Dorn, O.K. Kester, P. Kowina, B. Zwicker
    GSI, Darmstadt, Germany
  • O.K. Kester
    IAP, Frankfurt am Main, Germany
  
  Funding: The work is funded by European Union FP7 within CRISP.
At the heavy ion LINAC at GSI, a novel scheme of non-invasive Bunch Shape Monitor has been tested with several ion beams at 11.4 MeV/u. The monitor’s principle is based on the analysis of secondary electrons as liberated from the residual gas by the beam impact. These electrons are accelerated by an electrostatic field, transported through a sophisticated electrostatic energy analyzer and an RF-deflector, acting as a time-to-space converter. Finally a MCP amplifies electrons and with a CCD camera the electron distribution is detected. For the applied beam settings this Bunch Shape Monitor is able to obtain longitudinal profiles down to a width of 400 ps with a resolution of 50 ps, corresponding to 2 degree of the 108 MHz accelerating frequency. Systematic parameter studies for the device were performed to demonstrate the applicability and to determine its resolution. The achievements and ongoing improvements for the monitor are discussed. 		 
poster icon Poster MOPC36 [2.665 MB]  
 
MOPC40 Measurement of Longitudinal Bunch Profile and Twiss Parameters in SNS LINAC laser, longitudinal, SCL, SNS 163
 
  • A.V. Aleksandrov, C. Huang, Y. Liu, A.P. Shishlo, A.P. Zhukov
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
We are reporting on the latest progress in the longitudinal beam profile and emittance diagnostics development at SNS. In order to characterize the longitudinal phase space of the beam in the SNS 1GeV proton LINAC the bunch profile needs to be measured with a few picosecond resolution. The original SNS set of diagnostics included only four interceptive Feschenko-style longitudinal profile monitors in the normal conducting part of the LINAC at 100MeV. Two recently added systems are: a non-interceptive laser scanner in the injector at 2.5MeV and a novel non-interceptive method for longitudinal Twiss parameters measurement using the beam position monitors in the Super Conducting LINAC (SCL) at 300MeV. This paper presents details of these two diagnostics and discusses their performance, resolution limitations and future development plans. 		 
poster icon Poster MOPC40 [8.865 MB]  
 
MOPF02 The Wire Scanner Control Sytem for C-ADS Injector-II controls, emittance, feedback, diagnostics 197
 
  • M. Li, X.C. Kang, R.S. Mao, J.X. Wu, Y.J. Yuan, J. Zhang, Y. Zhang, G. Zhu
    IMP, Lanzhou, People's Republic of China
  
  The C-ADS project is a strategic plan to solve the nuclear waste problem and the resource problem for nuclear power plants in China. The first step of this project is to build two 5-MeV test CW linac. The institute of Modern physics (IMP) is in charge of designing one of them. In order to measure the beam profile in this linac, a wire scanner system was designed and tested. In this paper, the mechanical design and control system of this wire scanner system are introduced. A real-time, closed loop control system is being developed and tested for more repeatable and accurate positioning of beam sense wires. All of the electronic and computational duties are handled in one the National Instruments compact RIO real-time chassis with a Field-Programmable Gate Array (FPGA). The beam test result of this system in IMP 320 KV beam line was present. The test result of this system and the measured beam profile result are discussed in this paper.  
 
MOPF15 Advanced uses of a Current Transformer and a Multi-Wire Profile Monitor for Online Monitoring of the Stripper Foil Degradation in the 3-GeV RCS of J-PARC injection, monitoring, proton, target 239
 
  • P.K. Saha, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, M. Kinsho, K. Okabe, R. Saeki, K. Yamamoto, Y. Yamazaki, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  We have established advanced and sophisticated uses of a Current Transformer (CT) and a Multi-Wire Profile Monitor (MWPM) for measuring as well as online monitoring of the stripper foil degradation during user operation of the 3-GeV Rapid Cycling Synchrotron (RCS) in Japan Proton Accelerator Research Complex (J-PARC). An incoming negative hydrogen beam from the Linac is stripped to a proton beam by using a stripper foil placed in the RCS injection area. Foil degradation such as, foil thinning and pinhole formation are believed to be signs of a foil breaking. A sudden foil breaking is not only a load on the accelerator downtime but also raises maintenance issues. In a high intensity accelerator like RCS, a proper monitoring system of the foil is thus important in order to avoid such above issues by replacing the foil with a new one in the scheduled maintenance day. The thickness of the stipper foil used for the present 181 MeV injection energy is 200 ug/cm2, where a change of foil thickness as low as 1% or even less has already been successfully monitored by utilizing the presented method. Measured data for the last 6 months operation of the RCS will be presented.  
poster icon Poster MOPF15 [1.591 MB]  
 
MOPF27 A Beam Current Monitor for the VECC Accelerator gun, diagnostics, vacuum, radiation 275
 
  • W.R. Rawnsley, R.E. Laxdal
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  
  TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.  
poster icon Poster MOPF27 [1.314 MB]  
 
TUAL2 Commissioning the New LCLS X-band Transverse Deflecting Cavity with Femtosecond Resolution FEL, LCLS, undulator, electron 308
 
  • P. Krejcik, F.-J. Decker, Y. Ding, J.C. Frisch, Z. Huang, J.R. Lewandowski, H. Loos, J.L. Turner, J.W. Wang, M.-H. Wang, J.J. Welch
    SLAC, Menlo Park, California, USA
  • C. Behrens
    DESY, Hamburg, Germany
  
  Funding: This work was supported by Department of Energy Contract No. DE-AC0276SF00515
The new X-band transverse deflecting cavity began operation in May 2013 and is installed downstream of the LCLS undulator. It is operated at the full 120 Hz beam rate without interfering with the normal FEL operation for the photon users. The deflected beam is observed on the electron beam dump profile monitor, which acts as an energy spectrometer in the vertical plane. We observe, on a pulse by pulse basis, the time resolved energy profile of the spent electron beam from the undulator. The structure is powered from a 50 MW X-band klystron, giving a 48 MV kick to the beam which yields a 1 fs rms time resolution on the screen. We have measured the longitudinal profile of the electron bunches both with the FEL operating and with the lasing suppressed, allowing reconstruction of both the longitudinal profile of the incoming electron beam and the time-resolved profile of the X-ray pulse generated in the FEL. We are immediately able to see whether the bunch is chirped and which parts of the bunch are lasing, giving us new insight into tuning the machine for peak performance. The performance of the system will be presented along with examples of measurements taken during LCLS operation. 		 
slides icon Slides TUAL2 [9.210 MB]  
 
TUBL1 NSLS-II BPM and Fast Orbit Feedback System Design and Implementation BPM, feedback, storage-ring, controls 316
 
  • O. Singh, B. Bacha, A. Blednykh, W.X. Cheng, J.H. De Long, A.J. Della Penna, K. Ha, Y. Hu, B.N. Kosciuk, M.A. Maggipinto, J. Mead, D. Padrazo, I. Pinayev, Y. Tian, K. Vetter, L.-H. Yu
    BNL, Upton, Long Island, New York, USA
  
  The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized, ultra-low emittance, 3 GeV electron storage ring, linac pre-injector and full energy booster synchrotron. The low emittance requires high performance beam position monitor systems, providing measurement to better than 200 nm resolution; and fast orbit feedback systems, holding orbit to similar level of orbit deviations. The NSLS-II storage ring has 30 cells, each deploying up to 8 RF BPMs and 3 fast weak correctors. Each cell consists of a "cell controller", providing fast orbit feedback system infrastructure. This paper will provide a description of system design and summarize the implementation and status for these systems.  
slides icon Slides TUBL1 [5.225 MB]  
 
TUPC01 Overview of the European Spallation Source Warm Linac Beam Instrumentation ESS, diagnostics, emittance, ion 346
 
  • B. Cheymol, C. Böhme, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson, T.J. Shea, L. Tchelidze
    ESS, Lund, Sweden
  
  The normal conducting front end of the European Spallation source will accelerate the beam coming for the ion source up to 90 MeV. The ESS front end will consist in an ion source, a low energy beam transport line, a radio frequency quadrupole, a medium energy beam transport line and a drift tube linac. The warm linac will be equipped with beam diagnostics to measure the beam position, the transverse and longitudinal profile as well as beam current and beam losses. This will provide efficient operation of ESS, and ensure keeping the losses at a low level. This paper gives an overview of the beam diagnostics design and their main features.  
 
TUPC06 Status of Beam Diagnostic Systems for TRIUMF Electron Linac BPM, diagnostics, target, electron 361
 
  • V.A. Verzilov, P.S. Birney, D.P. Cameron, P. Dirksen, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  • J.M. Abernathy, D. Karlen, D.W. Storey
    Victoria University, Victoria, B.C., Canada
  
  TRIUMF laboratory is currently in a phase of the construction of a superconducting 50 MeV 10 mA cw electron LINAC to drive photo-fission based rare radioactive isotope beam (RIB) production. The project imposes certain technical challenges on various accelerator systems including beam diagnostics. In the first place these are a high beam power and strongly varying operating modes ranging from microsecond beam pulses to the cw regime. Diagnostics development interleaves with the construction of the diagnostics instrumentation required for the test facility which delivered the first beam in Fall of 2011. The paper reports the present status of various diagnostics systems along with measurement results obtained at the test facility.  
 
TUPC13 System Overview and Design Considerations of the BPM System of the ESS Linac BPM, target, ESS, beam-position 388
 
  • H. Hassanzadegan, A. Jansson, R. Zeng
    ESS, Lund, Sweden
  • A.J. Johansson
    Lund University, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  • A. Young
    SLAC, Menlo Park, California, USA
  
  The ESS Linac will include in total more than 140 Beam Position Monitors of different sizes and types. The BPM system needs to measure the beam position, phase and intensity in all foreseen beam modes with a pulse rate of 14 Hz, duration of 2.86 ms and amplitude ranging form 5 mA to 62.5 mA. With respect to the BPM connection to the Machine Interlock System, the total response time must be less than 10 us. The signal level variations from one BPM to another along the Linac should be as small as possible to meet the requirements on the analog gain of the front-end electronics and the dynamic range of the digitizer card input. The other requirement is that the BPM system needs to give at least a rough estimation of the beam position and phase, even if the beam is significantly debouched, ex. during the Linac tuning phase. These requirements and their impact on the design of the BPM detector, the analog front-end electronics and the selection of the digitizer card are discussed in this paper along with a general description of the BPM system.  
poster icon Poster TUPC13 [3.050 MB]  
 
TUPC15 BPM Electronics Upgrade for the Fermilab H− Linac Based Upon Custom Downconverter Electronics BPM, controls, booster, beam-position 396
 
  • E.S.M. McCrory, N. Eddy, F.G.G. Garcia, S.U. Hansen, T. Kiper, M.Z. Sliczniak
    Fermilab, Batavia, USA
  
  As part of the Fermilab Proton Improvement Plan, the readout electronics for the Fermilab H− Linac has been upgraded. The new custom electronics provide a low cost solution to process the 2nd harmonic of the RF at 402.5MHz. A single 4 channel NIM-bin module is used to readout each 4 plate stripline BPM pickup with each module being locked to an external 805MHz machine reference from the low level RF. For each BPM a number of measurements are provided including average horizontal and vertical position, average intensity, and average relative phase for variable pulse lengths from a few μs up to 50~usec. The system is being exploited in a number of ways with new operations applications.  
poster icon Poster TUPC15 [1.731 MB]  
 
TUPC25 Design of the SwissFEL BPM System BPM, pick-up, XFEL, undulator 427
 
  • B. Keil, R. Baldinger, R. Ditter, W. Koprek, R. Kramert, F. Marcellini, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
    PSI, Villigen PSI, Switzerland
  
  SwissFEL is a Free Electron Laser (FEL) facility being constructed at PSI, based on a 5.8GeV normally conducting main linac. A photocathode gun will generate two bunches with 28ns spacing at 100Hz repetition rate, with a nominal charge range of 10-200pC. A fast beam distribution kicker will allow to distribute one bunch to a soft X-ray undulator line and the other bunch to a 0.1nm hard X-ray undulator line. The SwissFEL electron beam position monitor (BPM) system will employ three different types of dual-resonator cavity BPMs, since the accelerator has three different beam pipe apertures. In the injector and main linac (38mm and 16mm aperture), 3.3GHz cavity BPMs will be used, where a low Q of ~40 was chosen to minimize crosstalk of the two bunches*. In the undulators that just have single bunches and 8mm BPM aperture, a higher Q will be chosen. This paper reports on the development status of the SwissFEL BPM system. Synergies as well as differences to the E-XFEL BPM system** will also be highlighted.
* F. Marcellini et al., "Design of Cavity BPM Pickups For SwissFEL", Proc. IBIC'12, Tsukuba, Japan, 2012.
** B. Keil et al., "The European XFEL BPM System", Proc. IPAC'10, Kyoto, Japan, 2010. 		 
poster icon Poster TUPC25 [1.074 MB]  
 
TUPC26 Beam-line Diagnostics at the Front End Test Stand (FETS), Rutherford Appleton Laboratory, Oxfordshire, UK BPM, rfq, emittance, ion-source 431
 
  • G.E. Boorman, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • G.E. Boorman, S.M. Gibson
    JAI, Egham, Surrey, United Kingdom
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • S.R. Lawrie, A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  The H− ion source and beam-line at FETS will require the beam current and beam position to be continually monitored. Current transformer toroids will measure the beam current and beam position monitors (BPM) will determine the beam position. The ion source delivers pulses at a rate of 50Hz with a current up to 60mA, each pulse is 2ms long, and a 324MHz micro-bunch structure imposed by the radio frequency quadrapole (RFQ) accelerating structure. The toroid outputs will be acquired on a fast oscilloscope. The BPM design is still under consideration (shorted strip-line or button type) but the processing for both types is similar and has been designed, with simulated measurements made. Each BPM uses four pickups, at a frequency of 324MHz, which are mixed using RF electronics to an intermediate frequency of 10.125MHz. The resulting signals are then digitized at 40.500MHz and processed in an FPGA to produce the position and phase of the beam at each BPM location, with a precision of better than 100μm and 0.05rad. The measurements from the toroids and BPMs will be via EPICS servers at every pulse.  
poster icon Poster TUPC26 [0.660 MB]  
 
TUPC37 Presentation of the Smith-Purcell Experiment at SOLEIL radiation, SOLEIL, vacuum, longitudinal 460
 
  • N. Delerue, J. Barros, S. Jenzer, M. Vieille Grosjean
    LAL, Orsay, France
  • L. Cassinari, M. Labat
    SOLEIL, Gif-sur-Yvette, France
  • G. Doucas, I.V. Konoplev, A. Reichold
    JAI, Oxford, United Kingdom
  • A. Faus-Golfe, N. Fuster Martinez, J. Resta-López
    IFIC, Valencia, Spain
  
  Funding: Work supported by seed funding from Université Paris-Sud, program 'Attractivité' and by the French ANR under contract ANR-12-JS05-0003-01.
The potential of Coherent Smith-Purcell radiation as a longitudinal bunch profile monitor has already been demonstrated and has recently been extended to the sub-picosecond range. As a critical step toward the construction of a single shot bunch profile monitor using Coherent Smith-Purcell radiation it is important to measure very accurately the distribution of such radiation. Optimum background suppression techniques need to be found and relatively cheap detectors suitable for the far infra-red need to be qualified. To perform these tasks a test stand has been installed at the end of the linac of the synchrotron SOLEIL. This test stand and the first results from its commissioning will be presented here. 		 
 
TUPF15 Overview of Laserwire Beam Profile and Emittance Measurements for High Power Proton Accelerators laser, emittance, ion, CERN 531
 
  • S.M. Gibson, G.E. Boorman, A. Bosco
    Royal Holloway, University of London, Surrey, United Kingdom
  • G.E. Boorman, A. Bosco, S.M. Gibson
    JAI, Egham, Surrey, United Kingdom
  • C. Gabor
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • T. Hofmann
    CERN, Geneva, Switzerland
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  Laserwires were originally developed to measure micron-sized electron beams via Compton scattering, where traditional wire scanners are at the limit of their resolution. Laserwires have since been applied to larger beam-size, high power H− ion beams, where the non-invasive method can probe beam densities that would damage traditional diagnostics. While photo-detachment of H− ions is now routine to measure beam profiles, extending the technique to transverse and longitudinal emittance measurements is a key aim of the laserwire emittance scanner under construction at the Front End Test Stand (FETS) at the RAL. A pulsed, 30kHz, 8kW peak power laser is fibre-coupled to motorized collimating optics, which controls the position and thickness of the laserwire delivered to the H− interaction chamber. The laserwire slices out a beamlet of neutralized particles, which propagate to a downstream scintillator and camera. The emittance is reconstructed from 2D images as the laserwire position is scanned. Results from the delivery optics, scintillator tests and particle tracking simulations of the full system are reviewed. Plans to deploy the FETS laser system at the Linac4 at CERN are outlined.  
poster icon Poster TUPF15 [9.196 MB]  
 
TUPF16 Analysis of Measurement Errors of INR Linac Ionization Beam Cross Section Monitor ion, space-charge, proton, simulation 535
 
  • S.A. Gavrilov, A. Feschenko, P.I. Reinhardt-Nickoulin, I.V. Vasilyev
    RAS/INR, Moscow, Russia
  • A. Feschenko, S.A. Gavrilov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  
  Residual gas ionization beam cross section monitors (BCSM) are installed at LEBT and HEBT of INR RAS proton linac to measure cross section, profiles and position of the beam. BCSMs provide two-dimensional non-destructive real-time beam diagnostics at LINAC operation with repetition frequency from 1 to 50 Hz, pulses duration from 0.3 to 170 μs and wide range of amplitudes, particle energy 400 keV and 209 MeV. The analysis of systematic measurements errors (accuracy) because of nonuniform electrostatic fields, determined by BCSM design features, is presented. New detector model, minimizing these nonuniformities, is shown. Besides that, the analysis of statistical errors (precision) due to the method features, in particular, ions thermal motion and a beam space charge, is done. The simulation results make it possible to estimate measured cross sections size, profiles and beam positions and to draw conclusions about the reliability of BCSM results for beams with various parameters.  
 
TUPF25 Beam Current Measurement System in CSNS LINAC beam-transport, vacuum, SNR, instrumentation 565
 
  • P. Li, F. Li, M. Meng, T.G. Xu
    IHEP, Beijing, People's Republic of China
  
  The China Spallation Neutron Source is being constructed at Dongguan, Guangdogn province. Before RCS Ring there are three beam transport sections in CSNS LINAC : LEBT, MEBT, LRBT, where various beam measurement monitors will be installed. Beam Current Transformers (BCTs) have been designed to measure beam macro-pulse current that will operate between 5mA to 80mA . The BCTs have the same inductance but different size in these three sections. Besides, beam parameters should be monitored also between the DTL four parts. There is no BCT but a FCT would be installed after DTL1 due to space limit. So this FCT is planned to measure the macro-pulse current, and we have to proceed the acquired data to show the original macro-pulse waveform due to the FCT’s low inductance.  
poster icon Poster TUPF25 [0.736 MB]  
 
WEPC03 Brookhaven 200 MeV Linear Accelerator Beam Instrumentation Upgrade instrumentation, diagnostics, vacuum, radiation 656
 
  • O. Gould, B. Briscoe, D.M. Gassner, V. LoDestro, R.J. Michnoff, J. Morris, D. Raparia, K. Sanders, W. Shaffer, C. Theisen, M. Wilinski
    BNL, Upton, Long Island, New York, USA
  • D. Persaud
    City College of The City University of New York, New York, USA
  
  The Brookhaven National Laboratory 200 MeV H− LINAC beam instrumentation equipment has been in operation for four decades with various changes implemented over this period. There is a need to upgrade the entire beam instrumentation system of the LINAC to improve the diagnostics of the beam from the Low Energy Beam Transport Line through the LINAC and into the LINAC Booster Transfer Line and BLIP line. Profile Monitors, Current Monitors, Beam Position Monitors, Loss Radiation Monitors, and Emittance Measurement devices are to be designed and implemented over the next three years. This upgrade will improve the operation reliability, beam quality and beam losses. Additional improvements will be obtained by designing the beam instrumentation system to integrate with other proposed diagnostics and malfunction detection and display upgrades in the LINAC Control Room to improve the overall performance of the LINAC.  
poster icon Poster WEPC03 [18.356 MB]  
 
WEPC06 Beam Instrumentation in the ESS Cold Linac BPM, ESS, cryogenics, instrumentation 667
 
  • C. Böhme, B. Cheymol, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  
  Parts of the linac of the European Spallation Source will consist of cryogenic cavity modules. In between these will be warm sections at room temperature to host amongst others the beam instrumentation. Each of the warm sections will host two beam position monitors and one or two other instruments, which might be a beam current monitor, invasive and non-invasive transverse beam profile monitor, bunch shape monitor, or halo monitor. The concept of the warm section layout will be shown and the planned instrumentation will be presented.  
 
WEPC14 Development of High Precision Beam Position Monitor Readout System with Narrow Bandpass Filters for the KEKB Injector Linac Towards the SuperKEKB BPM, positron, beam-position, KEKB 698
 
  • R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada
    KEK, Ibaraki, Japan
  
  The SuperKEKB accelerator complexes are now being upgraded to bring the world highest luminosity (L=8x1035/cm2/s). Hence, the KEKB Injector Linac is required to produce: electron: 20 mm mrad (7GeV, 5nC), positron: 10 mm mrad (4GeV, 4nC). To achieve this, the accelerator components have to be aligned within ± 0.1mm (1 σ). BPM is essential instrumentation for Beam Based Alignment, and is required one magnitude better position resolution to get better alignment results. Since current BPM readout system using oscilloscopes has ~50um position resolution, we decided to develop high precision BPM readout system with narrow bandpass filters. It handles two bunches with 96ns interval and has a dynamic range between 0.1nC (for photon factory) to 10nC (positron primary). To achieve these criteria, we adopt semiconductor attenuators and optimized two-stage Bessel filters at 300MHz center frequency to meet both time and frequency domain constraints. To correct position drift due to gain imbalance during operation, calibration pulses are output to the BPM between beam cycles (20ms). The beam position and charge calculations are performed by onboard FPGA to achieve fast readout cycle.  
poster icon Poster WEPC14 [3.039 MB]  
 
WEPC15 Development of the Beam Position Monitors System for the LINAC of SPIRAL2 BPM, SPIRAL2, ion, transverse 702
 
  • P. Ausset, M. Ben Abdillah, J. Lesrel, E. Marius
    IPN, Orsay, France
  • T. Ananthkrishnan, S.K. Bharade, G. Joshi, P.D. Motiwala, C.K. Pithawa
    BARC, Trombay, Mumbai, India
  • V. Nanal, R.G. Pillay
    TIFR, Mumbai, India
  
  The SPIRAL 2 facility will deliver stable heavy ion and deuteron beams at very high intensity, producing and accelerating light and heavy rare ion beams. The driver will accelerate between 0.15mA and 5 mA deuteron beam up to 20 MeV/u and q/A=1/3 heavy ions up to 14.5 MeV/u. It is being built on the site of the Grand Accelerator National d’Ions Lourds at CAEN (France) The accurate tuning of the LINAC is essential for the operation of SPIRAL2 and requires from the Beam Position Monitor (BPM) system the measurements of the beam transverse position, the phase of the beam with respect to the radiofrequency voltage and the beam energy. This paper addresses the advancement made during the last twelve months on the realization of the 22 BPM required for the SPIRAL 2 LINAC. The BPM sensors are now completed and tested. The design of the acquisition card for the BPM is given and will be described. The prototype card is now under test and the first results are given. The aim is to verify the main parameters: sensitivity, position and phase measurement and the appropriate behavior of the BPM acquisition card in all cases (pulsed, electrode signal reconstruction, interlock, post mortem)  
 
WEPC17 Design and Simulation of Beam Position Monitor for the CADS Injector I Proton Linac BPM, simulation, pick-up, impedance 710
 
  • Y.F. Sui, J.S. Cao, H.Z. Ma, Q. Ye, J. Yue
    IHEP, People's Republic of China
  
  Funding: Work supported by the National Natural Science Foundation of China (NO. 11205172)
Beam Position Monitors (BPM) based on both capacitive and stripline pick-ups are designed for the China Accelerator Driven Subcritical system (C-ADS) Injector I proton LINAC. The BPM will be installed to measure the transverse beam position in the LINAC, of which the beam parameters are listed as current 10mA, energy 10MeV and the repetition frequency 325MHz. This contribution presents the status of the BPM design development and focuses on the design of the pick-ups and CST Particle Studio simulation results, including impedance, sensitivity, time domain, frequency domain response, etc. The main goal of the simulation is optimization of the mechanical design. 		 
 
WEPC19 Performance of Injection Beam Position Monitors in the J-PARC RCS injection, BPM, monitoring, bunching 716
 
  • N. Hayashi, P.K. Saha
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  It is important to monitor the injected beam trajectory and position into a synchrotron ring. In the J-PARC RCS, there are two specialized beam position monitors (BPM) in the first arc section in order to perform continuous monitoring. They detect the linac RF frequency 324 MHz or its second harmonics, these contributions quickly decrease after a few turns in the ring. Therefore, they are sensitive only just injected beam. The RCS adopts the multi-turn injection and transverse painting. These monitors are useful to check the beam behavior on-line.  
 
WEPC20 Bunch Extension Monitor for LINAC of SPIRAL2 facility ion, MCP, photon, diagnostics 720
 
  • R.V. Revenko, J.L. Vignet
    GANIL, Caen, France
  
  Funding: This work is funded in frame of CRISP project.
Measurements of the bunch longitudinal shape of beam particles are crucial for optimization and control of the LINAC beam parameters and maximization of its integrated luminosity. The non-interceptive bunch extension monitor for LINAC of SPIRAL2 facility is being developed at GANIL. The five bunch extension monitors are to be installed on the entrance of LINAC between superconducting cavities. The principle of monitor operation is based on registration of x-rays induced by ions of accelerator beam and emitted from thin tungsten wire. The monitor consists of two parts: system for wire insertion and positioning and x-ray detector based on microchannel plates. The prototype of detector has been developed and was tested using protons and heavy ions beams. 		 
poster icon Poster WEPC20 [9.366 MB]  
 
WEPC23 Design of an Ultra-Compact Stripline BPM Receiver using MicroTCA for LCLS-II at SLAC BPM, SLAC, LCLS, beam-position 731
 
  • C. Xu, S. Babel, S. L. Hoobler, R.S. Larsen, J.J. Olsen, S.R. Smith, T. Straumann, D. Van Winkle, A. Young
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515
The Linac Coherent Light Source II (LCLS II) is a free electron laser (FEL) light source. LCLS II will be able to produce 0.5 to 77 Angstroms soft and hard x-rays. In order to achieve this high level of performance, the electron beam needs to be stable and accurate. The LCLS II stripline BPM system has a dynamic range of 10pC to 1nC beam charge. The system has a 3.5 micrometer resolution at 250pC beam charge in an one inch diameter stripline BPM structure. The BPM system uses the MicroTCA physics platform that consists of analog front-end (AFE) and 16-bit analog to digital convertor (ADC) module. The paper will discuss the hardware design, architecture, and performance measurements on the SLAC LINAC. The hardware architecture includes bandpass filter at 300MHz with 15 MHz band-width, and BPM calibration process without communicating with the CPU module. The system will be able to process multibunch beams with 40ns spacing. 		 
poster icon Poster WEPC23 [1.769 MB]  
 
WEPF09 Profile and Emittance Measurements at the CERN LINAC-4 3 MeV Test Stand emittance, transverse, rfq, CERN 826
 
  • F. Zocca, E. Bravin, M. Duraffourg, G.J. Focker, D. Gerard, U. Raich, F. Roncarolo
    CERN, Geneva, Switzerland
  
  A new 160 MeV H− Linac named Linac-4 will be built at CERN to replace the old 50 MeV proton Linac. The ion source, the 3 MeV RFQ and the medium energy transport (MEBT) hosting a chopper, have been commissioned in a dedicated test stand. Wire grids and wire scanners were used to measure the transverse beam profile and a slit/grid emittance meter was installed on a temporary test bench plugged at the RFQ and MEBT exit in different stages. The emittance meter slit was also used as a scanning scraper able to reconstruct the transverse profile by measuring the transmission with a downstream current transformer. On the same measurement bench, a spectrometer in conjunction with a wire grid allowed measuring the energy spread of the particles. This paper summarizes the measurement results that allowed characterizing the 3 MeV beam and discusses the present understanding of monitor performance.  
 
WEPF10 Wire Scanner Design for the European Spallation Source ESS, proton, CERN, diagnostics 830
 
  • B. Cheymol, A. Jansson, T.J. Shea
    ESS, Lund, Sweden
  
  The European Spallation Source (ESS), to be built in the south of Sweden, will use a 2 GeV superconducting LINAC to produce the world's most powerful neutron source with a beam power of 5 MW. The beam power is a challenge for interceptive beam diagnostics like wire scanner, the thermal load on intercepting devices implies to reduce the beam power in order to preserve the device integrity. For nominal operation, non-disturbing techniques for profile measurements are planned, while for the commissioning phase, accurate measurements and cross checking, wire scanners will be used. This paper describes the preliminary design of the wire scanner system in the normal conducing LINAC as well as in the superconducting LINAC.  
 
WEPF30 System Overview and Preliminary Test Results of the ESS Beam Current Monitor System ESS, beam-losses, controls, monitoring 891
 
  • H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  
  The ESS Linac will include in total 21 Beam Current Monitors, mostly of ACCT type, to measure the average current over the 2.86 ms beam pulse, the pulse charge and the pulse profile. It is also planned to use a few Fast Current Transformers to check the performance of the fast beam choppers with a rise time as short as 10 ns. In addition to the absolute current measurement, the BCM system needs to measure the differential beam current and act on the Machine Interlock System if the difference exceeds some thresholds. The differential current measurement is particularly important in the low energy part of the Linac, where Beam Loss Monitors cannot reliably detect beam losses. This paper gives an overview of the ESS BCM system and presents some preliminary test results with a commercial ACCT and MTCA.4 electronics.  
poster icon Poster WEPF30 [6.267 MB]  
 
WEPF32 Measurement and Control of the Beam Energy for the SPIRAL2 Accelerator pick-up, controls, SPIRAL2, rfq 897
 
  • W. Le Coz, C. Doutresssoulles, C. Jamet, G. Ledu, S. Loret, C. Potier de courcy
    GANIL, Caen, France
  
  The first part of the SPIRAL2 facility, which entered last year in the construction phase at GANIL in France, will be composed of an ion source, a deuteron/proton source, a RFQ and a superconducting linear accelerator delivering high intensities, up to 5 mA and 40 MeV for the deuteron beams. As part of the MEBT commissioning, the beam energy will be measured on the BTI (Bench of Intermediate Test) at the exit of the RFQ. At the exit of the LINAC, the system has to measure but also control the beam energy. The control consists in ensuring that the beam energy is under a limit by taking account of the measurement uncertainty. The energy is measured by a method of time of flight, the signal is captured by non-intercepting capacitive pick-ups. This paper presents also the results obtained in terms of uncertainties and dynamics of measures.  
 
WEPF33 Measurement and Control of the Beam Intensity for the SPIRAL2 Accelerator controls, SPIRAL2, ion, monitoring 900
 
  • S.L. Leloir, T.A. André, B. Ducoudret, C. Jamet, G. Ledu, C. Potier de courcy
    GANIL, Caen, France
  
  The phase 1 of the SPIRAL2 facility is under construction at the GANIL (Caen, France). The accelerator including a RFQ and a superconducting linac will product deuteron, proton and heavy ion beams in a wide range of intensities and energies (beam power range: a few 100W to 200kW). The measurements of the beam intensities are ensured by several AC and DC Current Transformers (ACCT/DCCT). These measurements are required for the accelerator tuning and the beam controls for safety requests during the daily operation. The uncertainty has to be taken into account to determine the threshold value. This paper presents the measuring chain description of ACCT/DCCT, the signal processing by integration and the uncertainty studies.  
poster icon Poster WEPF33 [3.132 MB]  
 
THAL2 A New Differential and Errant Beam Current Monitor for the SNS Accelerator SCL, SNS, beam-losses, target 921
 
  • W. Blokland
    ORNL, Oak Ridge, Tennessee, USA
  • C.C. Peters
    ORNL RAD, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725
A new Differential and errant Beam Current Monitor (DBCM) is being implemented for the Spallation Neutron Source's Medium Energy Beam Transport (MEBT) and Super Conducting linac (SCL) accelerator sections. This new current monitor will abort the beam when the difference between two toroidal pickups exceeds a threshold. The MEBT DBCM will protect the MEBT chopper target while the SCL DBCM will abort beam to minimize fast beam losses in the SCL cavities. The new DBCM will also record instances of errant beam such as beam drop-outs to assist in further optimization of the SNS Accelerator. A software Errant Beam Monitor was implemented on the regular BCM hardware to study errant beam pulses. The new system will take over this functionality and will also be able to abort beam on pulse to pulse variations. as it is based on the FlexRIO hardware programmed in LabVIEW FPGA and can abort beam in 5 us. This paper describes the development, implementation, and initial test results of the DBCM as well as errant beam examples. 		 
slides icon Slides THAL2 [9.413 MB]